Adding mocks for the flag service

[serroba]

No description provided.

[Copilot]

Pull request overview

This PR introduces mock-based testing for the handler package by adding a FlagService interface and using gomock for test isolation. The refactoring improves test maintainability and focuses handler tests on handler-specific behavior rather than integration with the service layer.

• Defines a FlagService interface to enable mocking
• Replaces integration-style tests with unit tests using gomock mocks
• Removes the custom failingRepository test helper in favor of mock expectations

Reviewed changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/handler/handler.go	Introduces the FlagService interface with Create and Evaluate methods, updates Handler to depend on the interface, and adds go:generate directive for mock generation
internal/handler/mock_service_test.go	Generated mock implementation of FlagService using mockgen for use in handler tests
internal/handler/handler_test.go	Refactors all handler tests to use mocked FlagService instead of concrete implementations, removes the failingRepository helper, and renames one test for clarity
go.mod	Adds go.uber.org/mock v0.6.0 as an indirect dependency
go.sum	Adds checksums for go.uber.org/mock v0.6.0

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (17ae615) to head (28c3561).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            6         6           
  Lines          176       176           
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  Hits           176       176           

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